The invention concerns an X-ray or neutron-optical analysis device with means for directing radiation from a source onto a sample and with a detector having n substantially identical detector elements Di which are disposed parallel to each other in a first direction, and which extend in strips in a second direction y, wherein i=1, . . . n, for one-dimensional spatially-resolved detection of radiation reflected, scattered or diffracted by the sample onto the detector, and comprising a detection electronics for processing the detector signals of the n detector elements Di, wherein the detection electronics reliably processes a maximum defined radiation intensity per detector element Di without overloading.
An X-ray analysis device of this type is disclosed in US 2002/0053641.
Scattering, diffraction and reflection of X-ray and neutron radiation are important methods for analyzing a structure. The diffraction of X-ray or neutron radiation can give e.g. information concerning the symmetry properties of the scattering (generally crystalline) material.
The detector disclosed in US 2002/0053641 has an array of adjacent strip-shaped detector elements for detecting the angle at which the radiation leaves the sample, relative to the incident beam. This permits one-dimensional spatially resolved acquisition of diffracted or scattered X-ray radiation. The location of a detector element is thereby a measure of the angular deflection of the radiation leaving the sample. Acquisition of spatially resolved intensity distributions (diffractograms) using such a device can therefore provide information about the lattice structure of the sample. In particular, for measurements performed with grazing incidence X-ray radiation, e.g. XRR measurements (x-ray reflection), the intensity within the acquired X-ray diffractogram decreases exponentially with distance such that the intensity region of the entire diffractogram extends over several orders of magnitude. Since the different detector elements are correspondingly illuminated with different intensities, the acquisition of X-ray diffractograms requires detectors having a very high dynamic range (several orders of magnitude). Conventional detectors become saturated at very high count rates and these regions provide no useful information. The effective, useful range of these conventional detectors is therefore limited.
A collimator is conventionally disposed in front of a one-dimensional detector during medical X-ray transmission measurements to block radiation in defined regions of the detector elements. Essentially only one shadow image is measured in this case. An arrangement of this type is described e.g. by A. Cabal et al. “Feasibility of silicon strip detectors and low noise multichannel readout system for medical digital radiography.” 6th Mexican Symposium on Medical Physics, Mexico, Mexico City, March 2002, American Institute of Physics Conference Proceedings, no 630, 2002, pp. 202-207, USA.
It is the object of the present invention to propose an X-ray or neutron-optical analysis device for detecting reflected, scattered or diffracted radiation which largely eliminates or at least reduces overloading of the detector elements.